The Light-Harvesting Chlorophyll a/b-Binding Polypeptides and Their Genes in Angiosperm and Gymnosperm Species

Pichersky, Eran; Jansson, Stefan

doi:10.1007/0-306-48127-8_28

Cited by 32 publications

(49 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3D). The turnover rate of the LHCPs in V. litorea or chromophytes in general has not been studied in detail (Green and Durnford, 1996;Pichersky and Jansson, 1996). The persistence of FCP in the symbionts is either due to extreme pigment-protein complex stability or fcp genes have been transferred to the sea slug nucleus where they are expressed along with the appropriate targeting signals to route them to the chloroplasts.…”

Section: Discussionmentioning

confidence: 99%

Mollusc-Algal Chloroplast Endosymbiosis. Photosynthesis, Thylakoid Protein Maintenance, and Chloroplast Gene Expression Continue for Many Months in the Absence of the Algal Nucleus

et al. 2000

View full text Add to dashboard Cite

Early in its life cycle, the marine mollusc Elysia chlorotica Gould forms an intracellular endosymbiotic association with chloroplasts of the chromophytic alga Vaucheria litorea C. Agardh. As a result, the dark green sea slug can be sustained in culture solely by photoautotrophic CO 2 fixation for at least 9 months if provided with only light and a source of CO 2 . Here we demonstrate that the sea slug symbiont chloroplasts maintain photosynthetic oxygen evolution and electron transport activity through photosystems I and II for several months in the absence of any external algal food supply. This activity is correlated to the maintenance of functional levels of chloroplast-encoded photosystem proteins, due in part at least to de novo protein synthesis of chloroplast proteins in the sea slug. Levels of at least one putative algal nuclear encoded protein, a light-harvesting complex protein homolog, were also maintained throughout the 9-month culture period. The chloroplast genome of V. litorea was found to be 119.1 kb, similar to that of other chromophytic algae. Southern analysis and polymerase chain reaction did not detect an algal nuclear genome in the slug, in agreement with earlier microscopic observations. Therefore, the maintenance of photosynthetic activity in the captured chloroplasts is regulated solely by the algal chloroplast and animal nuclear genomes.

show abstract

Section: Discussionmentioning

confidence: 99%

Mollusc-Algal Chloroplast Endosymbiosis. Photosynthesis, Thylakoid Protein Maintenance, and Chloroplast Gene Expression Continue for Many Months in the Absence of the Algal Nucleus

et al. 2000

View full text Add to dashboard Cite

show abstract

“…The neoxanthin-binding site may be different with respect to the two other sites. A search in the primary sequence of LHCII for putative xanthophyll-binding sites (29) did not yield additional sequence motifs other than the two L sites close to helices A and B. It can therefore be proposed that neoxanthin has its binding site made of pigment-pigment interactions rather than pigment-protein interactions as suggested by the changes in Chl b spectral properties in the neoxanthin-free protein.…”

Section: How Many Xanthophyll-binding Sites Are In Lhcii?-inmentioning

confidence: 94%

“…The angle of the ⑀-ring of lutein is the same as that of the epoxy rings of antheraxanthin and violaxanthin, which seems to substitute effectively for lutein in Arabidopsis mutants (30). The xanthophylls have been proposed to have binding sites on the hydrophilic loops composed by hydrophobic sequences interrupted by a polar residue (29) that would interact with hydroxyl groups of rings. Changes in the geometry of the interaction might lead to the conformational changes affecting energy transfer in the complex.…”

Section: Luteinin Violaxanthin and Zeaxanthin Are Bound To The L1 Amentioning

confidence: 99%

Carotenoid-binding Sites of the Major Light-harvesting Complex II of Higher Plants

Croce

Weiß

Bassi

1999

Journal of Biological Chemistry

237

273

View full text Add to dashboard Cite

Recombinant light-harvesting complex II (LHCII) proteins with modified carotenoid composition have been obtained by in vitro reconstitution of the Lhcb1 protein overexpressed in bacteria. The monomeric protein possesses three xanthophyll-binding sites. The L1 and L2 sites, localized by electron crystallography in the helix A/helix B cross, have the highest affinity for lutein, but also bind violaxanthin and zeaxanthin with lower affinity. The latter xanthophyll causes disruption of excitation energy transfer. The occupancy of at least one of these sites, probably L1, is essential for protein folding. Neoxanthin is bound to a distinct site (N1) that is highly selective for this species and whose occupancy is not essential for protein folding. Whereas xanthophylls in the L1 and L2 sites interact mainly with chlorophyll a, neoxanthin shows strong interaction with chlorophyll b, inducing the hyperchromic effect of the 652 nm absorption band. This observation explains the recent results of energy transfer from carotenoids to chlorophyll b obtained by femtosecond absorption spectroscopy. Whereas xanthophylls in the L1 and L2 sites are active in photoprotection through chlorophyll-triplet quenching, neoxanthin seems to act mainly in 1 O 2 * scavenging.Light energy for the photosynthesis of green plants is collected by an antenna system composed of many homologous proteins belonging to the Lhc multigene family (1). These pigment-protein complexes are organized around photosynthetic reaction centers to form supramolecular complexes embedded into the thylakoid membrane, accounting for ϳ70% of the pigment involved in plant photosynthesis. LHCII 1 is the most abundant light-harvesting complex in higher plants. The structure of this complex has been resolved at 3.4 Å by electron microscopy (2) and is formed by three hydrophobic transmembrane helices connected by hydrophilic loops and an amphipathic helix exposed to the luminal surface of the membrane. LHCII coordinates 7 Chl a, 5 Chl b, and 3-4 carotenoid molecules (lutein, neoxanthin, and a substoichiometric amount of violaxanthin) depending on the genotype (3) and the physiological state of the plant (4). In the structural model of LHCII (2), 2 xanthophyll molecules have been located in the center of the complex, forming an internal cross-brace interacting with helices A and B. These appear to be crucial for protein stabilization, as suggested by the fact that a stable LHCII complex cannot be obtained without lutein in refolding experiments (5, 6). Although the 2 central molecules were tentatively assigned to lutein (2), the structural resolution is insufficient for their identification and for the location of the xanthophyll molecule with respect to the 2 detected by structural analysis. The nature and location of the binding site for the third xanthophyll molecule are presently unknown. It is also unclear if the individual binding sites have different affinities for the three xanthophyll species.Carotenoids have at least five different roles in photosynthesis: 1) light h...

show abstract

“…These investigations demonstrated that despite the large similarity of the protein sequences of all Lhc proteins (12), differences exist with regard to pigment binding and spectroscopic properties. The LHC studied in the most detail is LHCIIb.…”

mentioning

confidence: 99%

Pigment Binding of Photosystem I Light-harvesting Proteins

Schmid

Potthast

Wiener

et al. 2002

Journal of Biological Chemistry

View full text Add to dashboard Cite

The Light-Harvesting Chlorophyll a/b-Binding Polypeptides and Their Genes in Angiosperm and Gymnosperm Species

Cited by 32 publications

References 63 publications

Mollusc-Algal Chloroplast Endosymbiosis. Photosynthesis, Thylakoid Protein Maintenance, and Chloroplast Gene Expression Continue for Many Months in the Absence of the Algal Nucleus

Mollusc-Algal Chloroplast Endosymbiosis. Photosynthesis, Thylakoid Protein Maintenance, and Chloroplast Gene Expression Continue for Many Months in the Absence of the Algal Nucleus

Carotenoid-binding Sites of the Major Light-harvesting Complex II of Higher Plants

Pigment Binding of Photosystem I Light-harvesting Proteins

Contact Info

Product

Resources

About